The invention relates to a method for managing drilling pipes, drilling tools, well tubing, and the like for ground drillings, particularly for accessing deposits of fossil fuels or geothermal reservoirs.
In order to explore and access petroleum and natural gas deposits generally ground drilling is required to considerable depths, because the drills must penetrate low-lying layers of rock or the operation occurs off-shore. The same applies for drilling in order, for example, utilizing natural geothermal water reservoirs for energy generation or accessing CO2-deposits.
In all these cases the drilling heading is generated by a drill bit or the like, which is located at the tip of a drill string, with the drill string comprising drilling pipes or an assembly of drilling pipes increasing in length when the drilling heading advances. The drive of the drill bit or another drilling tool occurs here from the earth surface or perhaps from a drilling platform, thus from the surface of the water, with either the drill string serving for the mechanic transmission of the drilling forces or a drilling liquid being pumped into the well, which hydraulically drives the drill bit. Generally, the drill string comprises steel pipes as the drill string so that the drill cuttings developing during the drilling process can be removed by the fluid conducted through the drill string upwards or out of the well. Frequently, a well hole casing is inserted to line the well coaxially in reference to the drill string.
In order to insert the drill string into the well, which becomes increasingly longer with the progress of the drilling process, parts of the drill string, pipeline parts, and the like each typically having a length of 12-20 m are provided in the proximity of the well and successively inserted into the well, with each part newly inserted into the well being fastened to the respectively previous part. The latter commonly occurs via threaded connections at the end of the parts.
Ground drilling normally starts in the vertical direction so that generally a drilling tower is erected, which lowers the individual string parts and the like vertically into the well. A pipe handler ensures the automatic engagement of horizontally aligned parts of the drill string, pipeline parts, etc. and ensures the pivoting of the grasped parts into a vertical position above the well, where it is accepted by the well hole—feeding device at the drilling tower.
The longer the drill string the more important it becomes to keep the time as short as possible for providing and inserting the individual parts to be inserted into the well. Here, the time for handling parts within the period of the overall drilling progress is multiplied here by the fact that from time to time it is necessary to pull the entire drill string out of the well, in order to, for example, replace a worn or damaged drill bit, and thereafter the drill string must once more be inserted into the well by reassembling it part by part. The life of the drill bit can be limited in difficult geological conditions to a few hours so that the pulling out, taking apart, reassembly, and reinsertion of the drill string must be repeated several times, with the number of parts to be handled growing with the progression of the drilling process.
In addition to the time required for handling the individual parts of the drill string, which should be kept as short as possible, it is also important to store the individual parts of a drill string pulled out of a well in an orderly fashion so that they can be reinserted into the borehole in an unchanged sequence. This is particularly of great importance when the drill string requires intermediate parts with particular features or tools at certain positions.